All fountains that are located in areas that receive freezing moisture in the winter need to be protected. Failing to cover them in the winter can cause damage to the parts that hold water. We offer a line of covers made to our strict standards to insure you fountain will be protected from damage in the winter months. They are made from UV stabilized nylon with a waterproof coating. The cover is grommeted around the bottom to be securied with the provided nylon cord. To determine size add at least 4 inches to the diameter of the largest bowl.